Pneumatic or hydraulic cardiac assist devices

ABSTRACT

The embodiments relate to cardiac assist devices that comprise a jacket that wraps the exterior of the heart, where the jacket comprises one or more pneumatic or hydraulic bladders. The pneumatic or hydraulic bladders are linked to a pump, and the pump fills the bladders with fluid and withdraws the fluid in a cycle to match beats of the heart to assist contraction and pumping of the heart in systole or to assist expansion and filling of the heart in diastole.

BACKGROUND

Congestive heart failure (CHF) is a debilitating and progressive diseasethat causes a heart to pump less efficiently over time. Typically, theheart has been weakened by an underlying problem, such as cloggedarteries, high blood pressure, a defect in heart muscles or heartvalves, or some other medical condition. Many symptoms and conditionsassociated with heart failure can be treated, but to date in many casesthe underlying impairment of the heart cannot.

One characteristic of heart failure is remodeling of the heart—that is,physical change to the size and shape of the heart and thickness of theheart wall. In many cases the wall of the left ventricle thins andstretches in places. The thinned portion of the myocardium is typicallyfunctionally impaired and other portions may grow or thicken tocompensate.

Typically, the heart enlarges as heart failure progresses, which seemsto be the result of the body trying to compensate for weakening heartmuscles. The heart can become so enlarged that the heart can no longerprovide an adequate supply of blood to the body. As a result,individuals afflicted with congestive heart failure often experienceshortness of breath and fatigue even with minimal activity. Also, as theheart enlarges, the heart valves may not adequately close, which furtherreduces the heart's ability to supply blood to the body.

Drug therapies have been developed to treat individuals afflicted withcongestive heart failure. A drug regimen of beta blockers, diuretics,and angiotensin-converting enzyme inhibitors (ACE inhibitors) aims toimprove the effectiveness of the heart's contractions and slow CHFprogression. Although drug therapy for heart failure can improve thequality of life and also modestly prolong survival, it is wellestablished that many of the currently available approaches do notrepresent satisfactory long-term treatment options for a large number ofpatients.

Once the disease progresses to the point that medication is no longereffective, the currently preferred options are a heart transplant or aventricular assist device (VAD). Approximately 550,000 new cases of CHFare diagnosed in the United States alone every year. Of these, at least75,000 individuals are candidates for a heart transplant. But more than50,000 men and women die every year waiting for a heart transplantbecause of a lack of donor hearts.

Only a few hundred VADs are implanted in the US each year. VAD use islimited because device implant surgery is highly invasive andcomplicated. Management of pump volume or pressure is difficult. VADsurgery adds insult to the heart because of the required surgicalconnections into the ventricle and aorta. But the largest contributor tocomplications from VAD implantation is the required direct interface ofthe device with the patient's blood. This can lead to clotting, strokes,and infection.

In addition to drugs, transplants, and VADs, heart failure has beentreated with cardiac jackets or restraint devices. These basicallyconsist of flexible material wrapped around the heart. A cardiac jacketis fitted around an enlarged heart to physically limit expansion of theheart during diastole. This may prevent further enlargement of theheart.

Improved methods and devices for treating heart failure and othercardiac diseases are needed.

SUMMARY

The embodiments relate to cardiac assist devices that comprise a jacketthat wraps the exterior of the heart, where the jacket comprises one ormore pneumatic or hydraulic bladders. The pneumatic or hydraulicbladders are linked to a pump, and the pump fills the bladders withfluid and withdraws the fluid in a cycle to match beats of the heart toassist contraction and pumping of the heart in systole or to assistexpansion and filling of the heart in diastole.

The pneumatic or hydraulic fluid may be a gas or a liquid. In oneembodiment, it is air. It may also be O₂, N₂, argon, or other suitablegas, or water, saline, or other suitable liquid.

One embodiment provides a device for treating cardiac diseasecomprising: (a) a cardiac jacket adapted to fit generally around theheart of a mammal, the jacket comprising an inner layer proximal to theheart and an outer layer distal to the heart, each composed of abiocompatible material, the inner and outer layers coupled to form oneor more fluid-tight seals that define one chamber generally overlayingthe right ventricle (the right chamber), or one chamber generallyoverlaying the left ventricle (the left chamber); (b) a first fluidpassageway linked to the right chamber or the left chamber; (c) a fluidreservoir linked to the first fluid passageway; and (d) a pump linked tothe fluid reservoir and adapted to pump fluid from the fluid reservoirinto the right chamber or the left chamber and to withdraw the fluidfrom the chamber in a cycle to expand the right chamber or the leftchamber during systole and contract the chambers during diastole toassist systolic pumping of the heart or diastolic refilling of the heartor both; wherein the chamber does not cover the apex of the heart and inoperation the jacket does not compress the apex of the heart upward;wherein the chamber has an apical border toward the apex of the heartand below the widest point of the heart and a base border toward thebase of the heart; wherein the fluid passageway is linked to the chambernear the apical border and below the widest point of the heart and thechamber expands and compresses the heart from near the apical border ofthe chamber toward the base border of the chamber.

Another embodiment provides a device for treating cardiac diseasecomprising: (a) a cardiac jacket adapted to fit generally around theheart of a mammal, the jacket comprising an inner layer proximal to theheart and an outer layer distal to the heart, each composed of abiocompatible material, the inner and outer layers coupled to form oneor more fluid-tight seals that define (i) one chamber or a plurality ofchambers collectively generally overlaying the right ventricle (theright chamber or chambers), and/or (ii) one chamber or a plurality ofchambers collectively generally overlaying the left ventricle (the leftchamber or chambers); (b) a first fluid passageway linked to the rightchamber or chambers; (c) a second fluid passageway linked to the leftchamber or chambers; (d) a fluid reservoir linked to the first andsecond fluid passageways; and (e) a pump linked to the fluid reservoirand adapted to pump fluid from the fluid reservoir into right chamber orchambers and the left chamber or chambers and to withdraw the fluid fromthe chambers in a cycle to expand the left chambers and/or the rightchambers during systole and contract the chambers during diastole toassist systolic pumping of the heart or diastolic refilling of the heartor both; wherein the chambers do not cover the apex of the heart and inoperation the jacket does not compress the apex of the heart upward; andwherein the one or more chambers overlaying the right ventricle arefluidically separated from the one or more chambers overlaying the leftventricle except through the fluid reservoir. Preferably the one or morechambers overlaying the left ventricle are delimited in part by a seamcoupling the inner and outer layers and overlaying the anterior sulcusof the heart, and by a seam coupling the inner and outer layers andoverlaying the posterior sulcus of the heart.

Another embodiment provides a system for treating heart diseasecomprising: (a) a device of the invention comprising a cardiac jacketand (b) a restraint jacket external to the cardiac jacket, the restraintjacket comprising a band of biocompatible material attached to anadjustable coupling mechanism, wherein the restraint jacket is adaptedto be adjustable in circumference to restrain outward expansion of thecardiac jacket and to hold at least a portion of the cardiac jacket in anarrower circumference about the heart than it would be held without therestraint jacket, and wherein the restraint jacket is composed offlexible material.

Another embodiment provides a method of treating heart failurecomprising: implanting a device of the invention or a system of theinvention comprising a device of the invention in a mammalian patient,preferably a human, suffering from heart failure, and pumping fluid inthe device with the pump to expand one or more chambers of the deviceand thereby assist pumping of the left ventricle and/or the rightventricle in the patient.

Another embodiment provides a method of treating heart failurecomprising: (a) implanting a device or system described herein fortreating heart failure in a patient suffering from heart failure, and(b) pumping fluid in the device with the pump to expand one or morechambers of the device and thereby assist pumping of the left ventricleand/or the right ventricle in the patient; and (c)(i) adjusting pressureor time course of pressure exerted on the left or right ventricle indiastole by the device or maximum expansion volume of the left or rightventricle allowed by the device in diastole, or (c)(ii) adjusting thepressure or the time course of pressure exerted on the left or rightventricle in systole by the device or the minimum volume of the left orright ventricle in systole, or both (c)(i) and (c)(ii).

Another embodiment provides a method of treating heart failurecomprising: (a) implanting a device or system described herein fortreating heart failure in a patient suffering from heart failure, and(b) pumping fluid in the device with the pump to expand one or morechambers of the device and thereby (i) assist pumping of the leftventricle and/or the right ventricle in the patient in systole, or (ii)restrain expansion of the left ventricle and/or the right ventricle inthe patient in diastole, or both (i) and (ii); wherein the step ofpumping fluid is adjusted at least once to adjust minimal or maximalexpansion of one or more of the one or more chambers (i) so as to adjustamount of assistance given by the device in pumping of the leftventricle and/or the right ventricle in the patient in systole, or (ii)so as to adjust amount of restraint applied by the device againstexpansion of the left ventricle and/or the right ventricle in thepatient in diastole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of the inner layer of the cardiac jacketin some embodiments, showing the inner layer of the cardiac jacket aswider or baggier toward the apex and tighter or narrower toward thebase.

FIG. 2 is a schematic drawing of the inner layer of the cardiac jacketin some embodiments, showing the inner layer of the cardiac jacket asthinner or more expandable toward the apex and thicker or lessexpandable toward the base.

FIG. 3 shows a chamber of the cardiac jacket in some embodiments laidflat showing passageways through the chamber that direct fluid flow fromthe apical border toward the base border to expand the chamber from theapical border toward the base border.

FIG. 4 shows one embodiment of a device of the invention comprising acardiac jacket.

FIG. 5 shows another embodiment of a device of the invention comprisinga cardiac jacket.

FIG. 6 shows another embodiment of a device of the invention comprisingelectrodes passing through conduits in the jacket to contact the heart.

FIG. 7 shows an embodiment with a cardiac jacket 11 and a restraintjacket 31.

DETAILED DESCRIPTION

One embodiment provides a device for treating cardiac diseasecomprising: first a cardiac jacket adapted to fit generally around theheart of a mammal, the jacket comprising an inner layer proximal to theheart and an outer layer distal to the heart, each layer composed of abiocompatible material, the inner and outer layers coupled to form oneor more fluid-tight seals that define one chamber generally overlayingthe right ventricle (the right chamber), or one chamber generallyoverlaying the left ventricle (the left chamber), or both the rightchamber and the left chamber. Alternatively, the inner and outer layerscan be coupled to form one or more fluid-tight seals that define aplurality of chambers that collectively generally overlay the rightventricle (the right chambers) or a plurality of chambers thatcollectively generally overlay the left ventricle (the left chambers),or both the right chambers and the left chambers. The device furthercomprises a fluid passageway linked to the right chamber or chambers orto the left chamber or chambers. The device further comprises a fluidreservoir linked to the fluid passageway; and a pump linked to the fluidreservoir and adapted to pump fluid from the fluid reservoir into theright chamber or chambers or the left chamber or chambers and towithdraw the fluid from the chambers in a cycle to expand the rightchamber(s) or the left chamber(s) during systole and contract thechambers during diastole to assist systolic pumping of the heart ordiastolic refilling of the heart or both.

In contraction, the device preferably should not compress the apex ofthe heart upward too much, because the apex is linked by the basingyfibers to the mitral valves and if the apex is raised it can lead tomitral regurgitation. Thus, preferably none of the chambers cover theapex of the heart. And preferably the jacket does not cover the apex ofthe heart. But some compression of the apex is permissible, provided itdoes not cause mitral regurgitation, so in some embodiments, the jacketcovers the apex of the heart and in some embodiments, the devicecompresses the apex of the heart.

In one embodiment, the jacket has an apical border towards the apex ofthe heart and apical to the widest point of the heart and wherein thejacket does not overlay the apex of the heart.

The devices compress the left ventricle or right ventricle, or both,preferably from the below the widest point of the heart, near to theapical end, upward toward the base of the heart. To accomplish that inparticular embodiments, the chamber has an apical border toward the apexof the heart and below the widest point of the heart and a base bordertoward the base of the heart; wherein the fluid passageway is linked tothe chamber near the apical border and below the widest point of theheart and the chamber expands and compresses the heart from near theapical border of the chamber toward the base border of the chamber.

The term “apical” or “toward the apical end” refers to the directiontoward the apex of the heart, which is basically lower in the body. Theterm “base border” means the border toward the base of the heart, whichis basically upper in the body.

Where a plurality of chambers collectively overlay the right ventricleor the left ventricle, the plurality of chambers collectively have anapical border toward the apex of the heart and a base border toward thebase of the heart; and the fluid passageway (or passageways) enter thechambers apical to the widest point of the heart.

Suitable hardware, including a hydraulic pump, a compliant reservoir androtary mechanical valve, together with appropriate actuating electronicscan all be implanted in the patient's body. If the power source is aninternal battery, then power may be transcutaneously transmitted intothe body to recharge this battery. Alternatively, the pump and powersource may be outside the body. For instance, they may be held in awearable vest. If the pump and power source are outside the body, atranscutaneous port is needed to transport the fluids of the systemthrough the skin to and from the chambers of the cardiac jacket.

When the chambers are inflated, the heart is squeezed to assist systolicaction. The chambers are deflated during diastolic action. If the wallsof the chambers are directly or indirectly attached to the myocardium,deflation of the chambers may pull the walls outward and assistdiastolic action. The walls of the chambers may be directly orindirectly attached to the myocardium by suturing a wall of the chamberto the myocardium or epicardium, or by an inner surface of the jacketthat promotes tissue growth to attach to the jacket. Diastolic actioncan also be assisted because of vacuum formed between the wall of theheart and the inner wall of the chambers, so that as the chambersdeflate they pull the wall of the heart outward with them. Vacuum ismore likely to form if the jacket is formed to fit closely to thecontours of the heart.

The shape of the jacket preferably fits closely to the contours of theheart, in order to keep the jacket in place. It can be custom made for aparticular patient based on the size and shape of that patient's heart,as determined by medical imaging. In other embodiments, one or morestandard sizes of the jacket are used. The basal (upper) border of thejacket is preferably toward the base of the heart from the widest pointof the heart and preferably has a smaller circumference than the widestpoint of the heart. Likewise, the apical border of the jacket ispreferably toward the apex from the widest point of the heart andpreferably has a smaller circumference than the widest point of theheart.

The device preferably does not compress either atrium of the heart.

Another embodiment provides a device for treating cardiac diseasecomprising: (a) a cardiac jacket adapted to fit generally around theheart of a mammal, the jacket comprising an inner layer proximal to theheart and an outer layer distal to the heart, each composed of abiocompatible material, the inner and outer layers coupled to formfluid-tight seals that define one chamber or a plurality of chamberscollectively generally overlaying the right ventricle (the right chamberor chambers), and one chamber or a plurality of chambers collectivelygenerally overlaying the left ventricle (the left chamber or chambers);(b) a first fluid passageway linked to the right chamber or chambers;(c) a second fluid passageway linked to the left chamber or chambers;(d) a fluid reservoir linked to the first and second fluid passageways;and (e) a pump linked to the fluid reservoir and adapted to pump fluidfrom the fluid reservoir into the right chamber or chambers and/or theleft chamber or chambers and to withdraw the fluid from the chambers ina cycle to expand the left chambers and/or the right chambers duringsystole and contract the chambers during diastole to assist systolicpumping of the heart or diastolic refilling of the heart or both;wherein the chambers do not cover the apex of the heart and in operationthe jacket does not compress the apex of the heart upward; wherein theone or more chambers overlaying the right ventricle are fluidicallyseparated from the one or more chambers overlaying the left ventricleexcept through the fluid reservoir.

A jacket of the invention is shown in FIG. 4. Jacket 11 generally wrapsaround the heart. It includes left chamber 12 overlaying the leftventricle and right chamber 13 overlaying the right ventricle. Seams 17are welds between an outer and an inner layer of material that make upthe jacket. The lateral seam 17A in this anterior view overlays theanterior sulcus of the heart and divides the right chamber from the leftchamber of the jacket. The jacket also has a seam 17C along the apicalborder of the jacket and a seam 17D along the base border of the jacket.Passageway 14 takes fluid from the pump and reservoir to and from theleft chamber and passageway 15 takes fluid from the pump and thereservoir to and from the right chamber. The base border of the jacketincludes a notch 16 around the pulmonary root 51.

Preferably the jackets of the invention, in addition to the chambers ofthe jacket, have an apical border towards the apex of the heart andbelow the widest point of the heart and the jacket does not overlay theapex of the heart.

The device with one or more chambers generally overlaying the rightventricle and one or more chambers generally overlaying the leftventricle in specific embodiments is adapted to separately control fluidflow into the right chamber(s) as compared to fluid flow into the leftchamber(s) to modulate assistance separately to the left ventricle andthe right ventricle. Thus, fluid flow to the left and right chambers canbe separately controlled or adjusted, e.g., by valves.

In specific embodiments, the jacket comprises a left chamber or chambersand not right chamber or chambers. In other embodiments, it comprises aright chamber or chambers and no left chamber or chambers. In otherembodiments, it comprises both a left chamber or chambers and a rightchamber or chambers.

The amount of pressure applied to the right and left ventricles can beseparately controlled, and the pressure on each ventricle applied by thedevice can be differentially controlled at different time points in thepumping cycle of the heart. Thus, the device can be tuned to assist theleft ventricle during systole, or the right ventricle during systole, orneither or both ventricles, and if both ventricles are assisted duringsystole, the pressure applied to the two ventricles can be different.Likewise, the device can assist expansion of the left ventricle or theright ventricle or both or neither during diastole. Assisting expansionof the ventricles can be done by applying negative pressure, with a wallor walls of the chambers of the jacket directly or indirectly attachedto the myocardium or epicardium. Also, the expansion of the left orright ventricles, or both or neither, can be resisted with positivepressure by the jacket during diastole. The resistance and positivepressure can be applied throughout diastole or only near the maximumexpansion of the heart in diastole. The amount of pressure applied tothe heart can also be varied at different points or phases of diastoleor systole. For diastole, we have applied the term “phasic diastolicrestraint” to describe this concept.

Thus, the devices and systems described herein can be adjusted or tunedto provide several different permutations of assistance to the heart.They can be used for specific assistance of congestive heart failurecharacterized by left ventricular systolic impairment, right ventricularsystolic impairment, left ventricular diastolic impairment, or rightventricular diastolic impairment, or different combinations thereof.

Thus, one embodiment provides a method of treating heart failurecomprising: (a) implanting a device or system described herein fortreating heart failure in a patient suffering from heart failure, and(b) pumping fluid in the device with the pump to expand one or morechambers of the device and thereby assist pumping of the left ventricleand/or the right ventricle in the patient; and (c)(i) adjusting pressureor time course of pressure exerted on the left or right ventricle indiastole by the device or maximum expansion volume of the left or rightventricle allowed by the device in diastole, or (c)(ii) adjusting thepressure or the time course of pressure exerted on the left or rightventricle in systole by the device or the minimum volume of the left orright ventricle in systole, or both (c)(i) and (c)(ii).

In one embodiment the method comprises adjusting pressure or time courseof pressure exerted on the left or right ventricle in diastole by thedevice or maximum expansion volume of the left or right ventricleallowed by the device in diastole. These adjustments can be applied tothe left and right ventricles separately or in a coordinated fashion.That is, one can apply pressure only to one ventricle, or greaterpressure to one than the other, or equal pressure to both, and one canseparately adjust the pressure applied to each ventricle.

In one embodiment, the method comprises separately adjusting thepressure exerted on the left ventricle or the right ventricle or both indiastole. For instance, the expansion of the chambers at their point ofminimal expansion in diastole can be adjusted to adjust the maximumexpansion volume of the left or right ventricle allowed in diastole.

In another embodiment, the method comprises adjusting the pressure ortime course of pressure exerted on the left or right ventricle insystole by the device or the minimum volume of the left or rightventricle in systole. For instance, the maximum expansion volume of theright chamber(s) or left chamber(s) (i.e., the chamber(s) overlaying theright ventricle or the chamber(s) overlaying the left ventricle) of thedevice can be adjusted to adjust the minimum volume of the right and/orleft ventricle in systole.

The adjustments may be based on measurements of the patient'sphysiology. In one embodiment, the method comprises measuring one ormore physiologic parameters of the patient, and then based on thephysiological parameters (c)(i) adjusting pressure or time course ofpressure exerted on the left or right ventricle in diastole by thedevice or maximum expansion volume of the left or right ventricleallowed by the device in diastole, or (c)(ii) adjusting the pressure orthe time course of pressure exerted on the left or right ventricle insystole by the device or the minimum volume of the left or rightventricle in systole, or both (c)(i) and (c)(ii).

The physiologic parameters may be parameters of optimal cardiacfunction. In a specific embodiment, the physiologic parameter is cardiacejection fraction. In specific embodiments, the one or morephysiological parameters may include cardiac output, cardiac volume, andcardiac pressure. In specific embodiments, the one or more physiologicalparameters may include pulmonary wedge pressure, pre-load pressure,and/or after-load pressure.

The parameters may be parameters that can be measured byechocardiography.

In a specific embodiment, the physiological parameter is arterial O₂saturation.

In specific embodiments of the methods, the method involves separatelyadjusting the pressure exerted on the left and/or right ventricle insystole.

In specific embodiments of the devices and systems of the invention, thedevice or system allows the heart to rotate freely in the chest cavityof the mammal.

In specific embodiments of the devices, the device is adapted to exertdifferent pressures on the left and right ventricles during systole (ordiastole). In specific embodiments of the methods, the methods involveexerting different pressures on the left and right ventricle in systole(or diastole).

In specific embodiments of the devices, the device is adapted to exertpressure on the left or right ventricle in systole (or diastole) andsubstantially no pressure on the other ventricle in systole (ordiastole). In specific embodiments of the methods, the method involvesexerting pressure on the left or right ventricle in systole (ordiastole) and substantially no pressure on the other ventricle insystole (or diastole).

In specific embodiments of the devices, the device is adapted to exertpressure on the left or right ventricle during diastolic expansion ofthe ventricles before maximum expansion during diastole of the ventricleor ventricles against which pressure is exerted. That is, it exertspressure during expansion of the chambers in diastole to restrain orslow the expansion. Likewise, in specific embodiments of the methods,the methods involve exerting pressure on the left or right ventricleduring diastolic expansion of the ventricles before maximum expansionduring diastole of the ventricle or ventricles against which pressure isexerted.

In other embodiments, the device is adapted to exert negative pressureon the left or right ventricle during diastolic expansion of theventricles to assist the left or right ventricle with diastolicexpansion. Likewise, in specific embodiments of the methods, the methodsinvolve exerting negative pressure on the left or right ventricle duringdiastolic expansion of the ventricles to assist diastolic expansion.

This negative pressure can be exerted where the inner wall of the jacketof the device is attached to the outer wall of the ventricle. Theattachment can be by surgically suturing the device to the wall of theventricle, or more preferably by tissue growing spontaneously to attachthe wall of the ventricle to the inner wall of the jacket. It can alsooccur where the inner wall of the jacket fits the outer wall of theventricle in a way that produces a vacuum between the inner wall of thejacket and the outer wall of the ventricle.

In specific embodiments, the device is further adapted to exert on theventricle or ventricles that receive negative pressure during diastolicexpansion, positive pressure at or near the point of maximum desireddiastolic expansion of the ventricle or ventricles.

In specific embodiments of the devices, the device is adapted to allowadjustment of the maximum expansion volume of the left or rightventricle during diastole that is allowed by the device by altering theamount of fluid in the chamber or chambers overlaying the left or rightventricle at the point of maximum diastolic expansion of the ventricle.

In specific embodiments, the device is adapted to allow separateadjustment of the maximum expansion volume of the left and rightventricles during diastole that is allowed by the device by altering theamount of fluid in the left and right chambers of the device at thepoint of maximum diastolic expansion of the ventricle.

This can be done, for instance, by using a valve to control the amountof fluid that flows into the chamber or chambers overlaying the rightventricle and another valve to control the amount of fluid that flowsinto the chamber or chambers overlaying the left ventricle. The openingand closing of the valves, as well as the direction and velocity ofpumping fluid into and out of the chambers by the pump, can becontrolled by the computerized generator.

Another embodiment of the invention provides a system for treatingcardiac disease comprising (a) a cardiac jacket as described herein,wherein the cardiac jacket comprises at least two dimensional transducerelements; and (b) a monitor electrically coupled to the transducerelements; wherein the transducer elements are adapted to measure signalsthat allow determination of distance between the at least two transducerelements and are adapted to transmit the signals to the monitor.

The devices can be used as passive diastolic restraint devices as well,with the advantage of being adjustable. Rather than pumping fluid intoand out of the chambers of the device in synchrony with a beat of theheart, the right and left chambers can be filled with fluid to a desiredlevel to create appropriate diastolic restraint against diastolicexpansion of the right ventricle or the left ventricle or both, and thenleft at that constant level of expansion to provide a constant diastolicrestraint. As with the active phase of the device, where one or morechambers of the device are expanded and contracted in synchrony with abeat of the heart, in the passive phase the level of restraint can alsobe adjusted by adjusting the expansion of the one or more chambers ofthe device.

Another embodiment provides a method of treating heart failurecomprising: (a) implanting a device or system described herein fortreating heart failure in a patient suffering from heart failure, and(b) pumping fluid in the device with the pump to expand one or morechambers of the device; and (c)(i) adjusting pressure exerted on theleft or right ventricle in diastole; wherein the expansion of the one ormore chambers is not changed over at least one hour or at least 24hours. In this mode, the device operates as a passive restraint devicerestraining expansion of the left or right ventricle in diastole but notassisting pumping in systole. In this passive mode also, the adjustmentof the pressure exerted by the device on the left or right ventricle canbe adjusted based upon physiologic parameters, as disclosed above.

Congestive heart failure patients and other heart patients may have moredamage to one ventricle than to the other. In these cases, it may beimportant to only compress the more damaged of the ventricles or todifferentially tailor the pressure exerted on each ventricle. With thechamber(s) overlaying the left ventricle fluidically separated from thechamber(s) overlaying the left ventricle, and with each chamber specificfor one ventricle, and with separate fluid passageways to the left andright chambers, it is possible to alter the amount of fluid that goestoward compressing the left ventricle as compared to the rightventricle. If only the left ventricle is impaired, only the leftchambers might be filled. Alternatively, both ventricles may becompressed, but the amount of fluid flowing into the left and rightchambers of the jacket may be tailored to fit the particular needs ofthe patient. This may be done, e.g., by valves separately controllingfluid flow into the left and right fluid passageways.

In one embodiment, the chambers of the cardiac jacket consist of onechamber generally overlaying the right ventricle and/or one chambergenerally overlaying the left ventricle.

In one embodiment, the first and second fluid passageways enter thechambers apical to the widest point of the heart. Preferably, the devicesqueezes the heart from the apical end toward the base in such as manneras to “scoop” blood upward in the ventricles. Having the fluidpassageways enter near the apical edge of the chambers or the jackethelps to achieve this because it causes the chambers to expand firstnear the apical edge.

In one embodiment, the device is adapted to squeeze the left ventricleand/or the right ventricle from the apical end toward the base. Toachieve this, as noted above, it is helpful to have the fluidpassageways enter the chambers near the apical end of the chambers ornear the apical border of the jacket. In other embodiments, the innerlayer of the jacket (which is the inner layer of the chambers) may becomposed of a variable thickness of material. This is shown in FIG. 2,where the apical region of the inner layer (shown as shaded) of thechambers is more expandable than the base region of the inner layer(shown without shading). Thus, when fluid fills the chamber, the apicalregion will expand more easily and thus expand faster than the baseregion, and squeezing the heart will begin at the apical region. In someembodiments, rather than two distinct regions, the expandability of thematerial in the inner layer may be in a gradient with highestexpandability near the apex and lower toward the base.

Similarly, in FIG. 1, the apical region of the inner layer of thechambers is wider than the outer layer when laid flat (panel A), butwhen welded to the outer layers is welded at the same width in theapical and base regions (panel B). Thus, the apical region is looser andcan expand more easily when fluid flows into the chamber. This allows itto expand first near the apical border and then toward the base border.

In a preferred embodiment, the inner layer need not be looser near theapical border or thinner or more flexible near the apical border thannear the base border. Rather, squeezing the heart first near the apicalborder of the jacket and then moving the pressure toward the base borderof the jacket is achieved by having channels within the right and/orleft chambers as shown in FIG. 3. The passageway that feeds fluid to thechamber links to the chamber near the apical border, and thus fluidfirst flows into and expands the channels within the chamber near theapical border and then flows upward through the channels toward the baseborder. In this way, the device scoops blood from the lower or apicalregions of the ventricle upward toward the aorta in the left ventricleor pulmonary artery in the right ventricle near the upper end of theventricles.

The inner layer of the chambers should preferably be more expandablethan the outer layer, so that expansion presses against and squeezes theheart wall. But the jacket may have the inner and outer layers of thechamber or chambers be the same material and equally expandable. Theinner and outer layers may be differentially expandable by beingcomposed of different materials and/or different thicknesses ofmaterials. They also can have different amounts of expandability bymaking the inner layer a larger area than the outer layer, when laidflat, so that the inner layer is “baggier” and can expand more. In apreferred embodiment, the inner layer and outer layer are both ELASTEON,a polyurethane from Aortech Corp., but the inner layer is thinner andmore expandable than the outer layer. Thus, the expansion with fluidfilling is predominantly inward, toward the heart wall. In oneembodiment we have made, the inner and outer layers are both identicalmedical grade polyurethanes, and the outer layer is thicker than theinner layer by a ratio of 7.5:4.

Thus, in a specific embodiment, the inner layer of the chamber orchambers is elastic and is more easily stretched than the outer layer ofthe jacket.

The material of the inner and outer layers of the chamber or chambersoverlaying the right ventricle can also have different characteristicsfrom those overlaying the left ventricle. For instance, the inner layerof the chambers overlaying the left ventricle may be more expandablethan the inner layer of the chambers overlaying the right ventricle, sothat the chambers tend to expand more onto the left ventricle than theright ventricle. Thus, in specific embodiments, the inner layer or outerlayer or both of the chamber or chambers overlaying the right ventriclemay have a different expandability as compared to the inner our outerlayer or both of the chamber or chambers overlaying the left ventricle.

In particular embodiments, the inner and outer layers are composed ofbiocompatible material, and the biocompatible material is or comprises asilicone, a polyurethane, or a silicone/urethane copolymer.

In a particular embodiment, the outer layer comprises a mesh layer. Themesh layer may be on the inner surface of the outer layer, on the outersurface of the outer layer, or in a sandwich between two continuouslayers of material that together with the mesh layer form the outerlayer.

Where there is one left chamber and one right chamber, the borders ofthe chambers should match the upper and lateral borders of theventricles. The lateral (or side) borders are the anterior sulcus andposterior sulcus. The upper border is the atrialventricular ring. Thus,in one embodiment, the left chamber is delimited in part by a seamcoupling the inner and outer layers and overlapping the anterior sulcusof the heart (seam 17A in FIG. 4) and a second seam coupling the innerand outer layers and overlaying the posterior sulcus of the heart. Wherea plurality of chambers collectively overlay the left ventricle, theplurality of chambers may be delimited in part by a first seam couplingthe inner and outer layers and overlapping the anterior sulcus of theheart and a second seam coupling the inner and outer layers andoverlaying the posterior sulcus of the heart.

In one embodiment, the right chamber is delimited in part by a firstscam coupling the inner and outer layers and overlapping the anteriorsulcus of the heart and a second seam coupling the inner and outerlayers and overlaying the posterior sulcus of the heart. Where aplurality of chambers collectively overlay the right ventricle, theplurality of chambers may be delimited in part by a first seam couplingthe inner and outer layers and overlapping the anterior sulcus of theheart and a second seam coupling the inner and outer layers andoverlaying the posterior sulcus of the heart.

In one embodiment, the left chamber is delimited in part by a seamcoupling the inner and outer layers and overlapping theatrialventricular ring of the heart (seam 17D in FIG. 4). Where aplurality of chambers collectively overlay the left ventricle, theplurality of chambers may be delimited in part by a seam coupling theinner and outer layers and overlapping the atrialventricular ring of theheart.

In one embodiment, the right chamber is delimited in part by a seamcoupling the inner and outer layers and overlapping theatrialventricular ring of the heart. Where a plurality of chamberscollectively overlay the right ventricle, the plurality of chambers maybe delimited in part by a seam coupling the inner and outer layers andoverlapping the atrialventricular ring of the heart.

In one embodiment, the inner and outer layers of the chambers arecomposed of polymer. In this case, the seams or couplings that formfluid-tight seals that define the chambers may be welds, e.g., thermalwelds or sonic welds.

The jacket is preferably formed so the upper border of the jacket isabove the widest point of the heart. As mentioned above, a good positionfor the upper border of the jacket or chambers is the atrialventricularring. The lower border of the jacket or chambers in some embodiments isabout 25-33% of the distance from the apex to the atrialventricular ring(i.e., closer to the apex and below the widest point of the heart).

In a preferred embodiment, the base border of the jacket forms a notchthat generally conforms to the pulmonary artery, as shown by notch 16 inFIG. 4.

The device can be customized for a particular patient. Heart size andshape varies between particular persons—in particular, diseased heartsvary in size and shape. Thus, the size and shape of the jacket isideally customized for a particular patient.

Seams between chambers do not expand or expand less than other areas,and where a chamber has inner seams, e.g., to form channels within thechamber, these do not expand or expand less than other areas. Thus,different areas of the chamber expand more than other areas. Likewise,different areas of the heart of a patient have been damaged more thanother areas. For instance, a myocardial infarction causes damage to aparticular section of the myocardium. In some embodiments of jacketdesigns, more pressure is exerted on particular areas of the wall of achamber than other areas of the same chamber. It may be desirable tocompress relatively healthy areas more than damaged areas or vice versa.Where the damage is old and has developed scarring and stiffness, it maybe desirable to compress and move the damaged areas more than thehealthy areas. In other cases, for instance in some cases where thedamage is new and still healing, it may be desirable to not compress thedamaged areas but to exert most of the compression on healthier areas ofthe ventricle. If more compression is desired on a damaged area thanhealthy areas, with customized jackets, a seam should overlay acomparatively healthy area of the heart and areas of greatest expansionin the chamber should overlay a comparatively damaged area. In FIG. 4,seam 17B is within the left chamber and does not separate chambers. In acustom made jacket, the location of this seam may be placed over acomparatively healthy area of the heart, while open areas of the leftchamber 12 may be placed over a comparatively damaged area of the leftventricle.

Thus, in one embodiment, the device is customized for a particularpatient, and the one or more chambers overlaying the left ventriclecomprise a seam that does not expand and the seam overlays acomparatively healthy area of the wall of the left ventricle of thepatient, and the one or more chambers comprises an area of greaterexpansion that overlays a comparatively damaged area of the leftventricle of the patient. In a particular embodiment, the comparativelydamaged area is an area of a myocardial infarction. The same can be donewith the right chamber and the right ventricle. The damaged areas can beidentified by methods known to persons of skill in the art, includingechocardiogram, PET scan, perfusion scan, and MRI.

Thus, in one embodiment, the device is customized to compress healthyand diseased or damaged myocardium differently.

In another embodiment, the jacket has drawstrings at its top and/orbottom borders to manually adjust the fit to fit a patient's heart. Inthis embodiment, the jacket has an apical border toward the apex of theheart and a base border toward the base of the heart and the jacket doesnot cover the apex of the heart, wherein the apical border or the baseborder of the jacket includes a cuff forming a passageway along theborder and includes an adjustable drawstring passing through the cuffthat can be adjusted in circumference and fastened at a particularcircumference fitting the heart of the patient.

In a particular embodiment, the drawstring comprises a hook-and-loopfastening mechanism. Many materials can be molded into hook-and-loopmechanism. For instance the drawstring can be a biocompatiblepolyurethane and the hook-and-loop fastening mechanism can be the samematerial. This is shown in FIG. 5 where cuff 18 along the apical bordermay include an inner drawstring (not shown). Likewise, cuff 19 along thebase border of the jacket may include an inner drawstring as well as orinstead of the apical border.

Instead of having a drawstring, the cuff along the top border of thejacket and/or the cuff along the bottom border of the jacket can beseparately inflatable chambers (apical border chambers and base borderchambers), separate from the one or more chambers that overlay the leftventricle and the one or more chambers that overlay the right ventricle.

Thus in one embodiment, the inner layer and outer layer of the jacketare coupled to form one or more fluid-tight seals that define one ormore chambers along the apical border of the jacket (apical borderchambers) and one or more chambers along the base border of the jacket(base border chambers); and the device comprises: (a) an apical borderfluid passageway linked to the apical border chambers and the fluidreservoir; and (b) a base border fluid passageway linked to the baseborder chambers and the fluid reservoir; wherein the apical borderchambers and the base border chambers are fluidically separated fromeach other and from the right chamber or chambers and the left chamberor chambers; wherein the pump is adapted to pump an adjustable amount offluid into the apical border chambers and the base border chambers toadjust how tightly the apical border and the base border of the jacketfit to a patient's heart. In another embodiment of the devices, thedevice comprises a computerized generator electrically linked to thepump to control the pump and electrically linked to one or more sensingand/or pacing electrodes electrically coupled to the heart.

In one embodiment, the electrodes are sensing electrodes wherein thedevice is adapted to detect contraction rhythm of the heart with thesensing electrodes and to generate electrical signals effective tocontrol the pump at a variable rate responsive to physiological activityof the mammal. The device is preferably adapted to begin expanding thechamber or chambers of the jacket in synchrony with an electrocardiogramphase detected in the heart, for instance, when the heart is in a QRelectrocardiogram phase.

In another embodiment, the electrodes are pacing electrodes and thedevice paces pumping of the heart muscle. Of course, the device can alsocomprise an adjustable rate pacemaker, where it comprises combinedsensing and pacing electrodes or both sensing and pacing electrodes.

In a specific embodiment of the device, one or more chambers of thejacket have an outer surface distal to the heart and an inner surfaceproximal to the heart, wherein the inner and/or outer layers of thechamber form one or more conduits through the chamber from the outersurface through the inner surface, wherein the conduits are exterior tothe chamber; and wherein the electrodes pass through the conduits tocontact the heart. To explain, the chamber can have a donutconfiguration with a hole in the middle through which electrodes canpass. This is shown in FIG. 6, where conduits 21 in the left chamber 12allow electrodes 22 to pass through the jacket to directly contact theheart.

In another embodiment, the inner layer of the jacket is contoured toform one or more channels raised above the surface of the heart, whereinthe electrodes pass through the channels to contact the heart. In thisway, the chambers do not directly contact the electrodes or do not pressagainst the electrodes when the chambers expand.

Another embodiment of the invention provides a system for treating heartdisease comprising: (a) a device comprising: (i) a cardiac jacketadapted to fit generally around the heart of a mammal, the jacketcomprising an inner layer proximal to the heart and an outer layerdistal to the heart, each composed of a biocompatible material, theinner and outer layers coupled to form fluid-tight seals that define onechamber generally overlaying the right ventricle (the right chamber), orone chamber generally overlaying the left ventricle (the left chamber);(ii) a first fluid passageway linked to the right chamber or the leftchamber; (iii) a fluid reservoir linked to the first fluid passageway;and (iv) a pump linked to the fluid reservoir and adapted to pump fluidfrom the fluid reservoir into the right chamber or the left chamber andto withdraw the fluid from the chambers in a cycle to expand the rightchamber or the left chamber during systole and contract the chambersduring diastole to assist systolic pumping of the heart or diastolicrefilling of the heart or both. The chamber does not cover the apex ofthe heart and in operation the jacket does not compress the apex of theheart upward. The chamber has an apical border toward the apex of theheart and below the widest point of the heart and a base border towardthe base of the heart; wherein the fluid passageway is linked to thechamber near the apical border and below the widest point of the heartand the chamber expands and compresses the heart from near the apicalborder of the chamber toward the base border of the chamber. The systemfurther comprises (b) a restraint jacket external to the cardiac jacket,the restraint jacket comprising a band of biocompatible materialattached to an adjustable coupling mechanism, wherein the restraintjacket is adapted to be adjustable in circumference to restrain outwardexpansion of the cardiac jacket and to hold at least a portion of thecardiac jacket in a narrower circumference about the heart than it wouldbe held without the restraint jacket.

A restraint jacket 31 is shown in FIG. 7. It may be raised to overlaycardiac jacket 11.

Use of the restraint jacket in some cases gives firmer control ofexpansion, so nearly all the expansion of the chambers is directedinward toward the heart, rather than both inward and outward (away fromthe heart). The restraint jacket also allows one to use a cardiac jacketthat is more standardized. The restraint jacket can be adjusted with itsadjustable coupling mechanism to fit the heart and constrain astandardized sized cardiac jacket. Thus, the system with the restraintjacket may be especially suitable in emergency situations, where thereis not time to manufacture a customized cardiac jacket for the patient.However, it is also usable in all situations, including with acustom-sized cardiac jacket. An advantage of the restraint jacket isthat it provides more restraint against outward expansion of thechambers than would otherwise be possible. Thus, it helps to forceexpansion of the chambers inward, where the expansion productively helpspump the heart.

Optionally, the restraint jacket does not include drawstrings along itscuffs and is not adjustable. It may be made in several standard sizesfor different users or customized for a particular patient.

The coupling mechanism of the restraint jacket may be any suitablecoupling mechanism. In one embodiment it may be a hook-and-loopmechanism. In another embodiment, the coupling mechanism is a knot,which can be manually tied by the surgeon.

Another embodiment provides a method of treating heart failurecomprising: implanting a device or system of the invention in a patientsuffering from heart failure, and pumping fluid in the device with thepump to expand one or more chambers of the device and thereby assistpumping of the left ventricle and/or the right ventricle in the patient.

In a particular embodiment, the patient is suffering from heart failuresecondary to myocarditis or traumatic cardiac injury. These aretemporary conditions, and patients need assistance only until theyrecover from the condition. At that point, the device can be removed orturned off.

An advantage of the devices of the invention over conventional leftventricular assist devices (LVADs) is that LVADs require creating anopening in the heart wall to allow blood to flow into the LVAD.Conventional LVADs have a tube passing through the wall of the leftventricle, and another tube passing through the wall of the aorta, and apump linking the two tubes. This requires placing a hole in the heart,which traumatizes an already damaged heart. Although some LVADs are usedtemporarily, this surgical damage to the heart makes it more difficultfor the heart to recover from a temporary condition such as myocarditisor traumatic cardiac injury and more difficult to remove the LVAD. Incontrast, the devices of the invention are placed over the heart withoutdamaging the heart. They can be implanted and removed without damagingthe heart. This makes them particularly well suited for treatingtemporary conditions.

Another key advantage of the present devices over conventional LVADs isthat the present devices have no blood contact. Conventional LVADs arebased on passing blood through artificial tubing and an artificial pump.The blood is constantly contacting artificial materials, which providesurfaces for clotting and damage to blood cells. Conventional LVADstherefore require that the patient be placed on anticoagulant therapy;the devices of the present invention do not.

Also, with a conventional LVAD the patient is entirely dependent on itfor pumping the blood. If the LVAD fails, the patient dies almostimmediately. With the present devices, if the device were to fail, thepatient would be no worse off than he was before the device wasimplanted. His own heart would continue to pump, just without assistancefrom the device.

There are several ways the devices of the invention can be used. Thechambers can inflate and the device assist pumping in systole with everybeat of the heart. But it can also be used to assist only every 2ndbeat, every 3rd beat, or every 4th beat. Alternatively, for somepatients it might be used only at nighttime during sleep. The patientcould then remove the external power pack, if the device uses anexternal power pack, and be free of it during the day, if he or she onlyneeds assistance part of the day. For many patients, it may be useful togradually wean the patient from the device. Thus, the device mayinitially assist with every beat all day, and then over time it couldshift to assisting with only every other beat or only at night or onlyduring the day.

The devices and cardiac jackets of the devices are preferably adapted tocontour to the heart wall as the heart squeezes. This is accomplished bycontouring of the inner wall of the one or more chambers or by makingthe inner wall of the chambers flexible enough that the inner wallconforms itself to the wall of the heart as the heart constricts andexpands. In this way, the device follows the helical squeezing patternof the heart. See, for example, www.helicalheart.com and Torrent-Guasp Fet al, Towards new understanding of the heart structure and function,Eur. J. Cardiothorac. Surg. 2005, 27(2):191-201.

In some embodiments, system comprises an active cardiac jacket asdescribed herein, with one or more chambers that inflate and deflate toassist the heart, and an inactive inner liner that wraps the heart andlies proximal to the heart from the cardiac jacket. The inner linerhelps to reduce abrasion or friction on the myocardium that might arisefrom the squeezing of the active cardiac jacket. Optionally, the systemcan also include a restraint jacket, distal to the heart from thecardiac jacket, as is described herein, in addition to the inactiveinner liner.

The inner liner is composed of a biocompatible material. In specificembodiments, it comprises polyurethane, a polyurethane/siliconecopolymer or polymer mixture, or collagen, or a polyurethane/collagencopolymer.

In one embodiment of the devices, the device does not further comprise arigid shell surrounding to cardiac jacket and restraining outwardexpansion of the cardiac jacket.

The devices are designed to compress enough to assist with pumping ofthe heart, but not so much as to close coronary arteries or veins andinterfere with coronary blood flow. Coronary blood flow, however, isprimarily during diastole, while compression by the devices is duringsystole, which lessens problems with partially or fully closing coronaryarteries or veins.

As will be noted, these devices are adaptable to diffentially compressone ventricle or another, and to differentially compress particularareas of the wall of a particular ventricle, e.g., compress healthytissue more or less than scarred or damaged tissue. Likewise, thedevices may temporally compress one ventricle or one area of the heartbefore another. For instance, the compression can go sequentially fromthe apex to the base, so as to pump blood upward in the ventricle beingcompressed.

Another embodiment of the invention provides a device for treatingcardiac disease comprising: a cardiac jacket adapted to fit generallyaround at least a portion of the heart, the jacket comprising an elasticor contractile material such that the jacket expands with diastole ofthe heart and contracts with systole of the heart around at least onepumping chamber of the heart; the cardiac jacket comprising at least twodimensional transducer elements; electrically coupled to a monitor;wherein the transducer elements are adapted to measure signals thatallow determination of distance between the at least two transducerelements and are adapted to transmit the signals to the monitor. Thetransducer elements are coupled to material of the cardiac jacket suchthat as the jacket expands or contracts with the beating of the heartand/or contraction and expansion of the chambers of the jacket, thetransducer elements move with the material of the jacket and thedistance between the transducer elements is monitored. Depending on howthe transducer elements are positioned, the distance is an indicator ofhow much the jacket contracts or expands, how much the heart or one orboth of its ventricles contracts and expands, and of how much one ormore chambers of the jacket contract or expand.

Thus, the measurements can be used to monitor heart function acrosstime. The measurements can be used, for instance, to give an estimate ofejection fraction. They can also show enlargement of the heart orreversal of enlargement over time.

The measurements can also be used as measurements of the volume of oneor more chambers of the jacket at different points in time. This can bea direct measurement of the volume of the one or more chambers and canbe used to facilitate adjusting the volume of the chambers, e.g., atmaximum diastolic expansion of the heart or maximum systolic contractionof the heart.

Dimensional transducers are known in the art. Suitable dimensionaltransducers are disclosed for instance in U.S. Pat. Nos. 7,307,374 and5,438,998. See also U.S. patent application Ser. No. 12/590,378.

Another embodiment provides a method of monitoring heart functioncomprising: monitoring variation of distance between at least twodimensional transducer elements coupled to a cardiac jacket adapted tofit generally around at least a portion of a heart, the jacketcomprising an elastic or contractile material such that the jacketexpands with diastole of the heart and contracts with systole of theheart around at least one pumping chamber of the heart.

All patents, patent documents, and non-patent references cited arehereby incorporated by reference.

What is claimed is:
 1. A method of treating heart failure comprising:(a) implanting a device for treating cardiac disease comprising: (I) acardiac jacket adapted to fit generally around the heart of a mammal,the jacket comprising an inner layer proximal to the heart and an outerlayer distal to the heart, each composed of a biocompatible material,the inner and outer layers coupled to form one or more fluid-tight sealsthat define (i) one or more chambers collectively generally overlayingthe right ventricle (the right chamber or chambers), and/or (ii) one ormore chambers collectively generally overlaying the left ventricle (theleft chamber or chambers); (II) a first fluid passageway linked to theright chamber or chambers; (III) a second fluid passageway linked to theleft chamber or chambers; (IV) a fluid reservoir linked to the first andsecond fluid passageways; and (V) a pump linked to the fluid reservoirand adapted to pump fluid from the fluid reservoir into right chamber orchambers and the left chamber or chambers and to withdraw the fluid fromthe chambers in a cycle to expand the left chambers and/or the rightchambers during systole and contract the chambers during diastole toassist systolic pumping of the heart or diastolic refilling of the heartor both; wherein the one or more chambers overlaying the right ventricleare fluidically separated from the one or more chambers overlaying theleft ventricle except through the fluid reservoir; (b) pumping fluid inthe device with the pump to expand one or more chambers of the deviceand thereby assist pumping of the left ventricle and/or the rightventricle in the patient; and (c)(i) adjusting pressure or time courseof pressure exerted on the left or right ventricle in diastole by thedevice or maximum expansion volume of the left or right ventricleallowed by the device in diastole, or (c)(ii) adjusting the pressure orthe time course of pressure exerted on the left or right ventricle insystole by the device or the minimum volume of the left or rightventricle in systole, or both (c)(i) and (c)(ii); wherein the methodcomprises adjusting pressure or time course of pressure exerted on theleft or right ventricle in diastole by the device or maximum expansionvolume of the left or right ventricle allowed by the device in diastole;wherein the method comprises separately adjusting the pressure exertedon the left and the right ventricle in diastole. 2-7. (canceled)
 8. Themethod of claim 1 wherein the method further comprises adjusting thepressure or the time course of pressure exerted on the left or rightventricle in systole by the device or the minimum volume of the left orright ventricle in systole.
 9. The method of claim 8 wherein the step ofadjusting pressure or time course of pressure occurs after the step ofpumping fluid in the device to assist in systole or restrain in diastoleis carried out through at least 10 cycles of beating of the heart. 10.The method of claim 8 wherein the step of adjusting pressure or timecourse of pressure is carried out on at least two occasions separated byat least two days. 11-17. (canceled)
 18. The method of claim 1 whereinthe method comprises exerting negative pressure on the left or rightventricle during diastolic expansion of the ventricles to assist theleft or right ventricle with diastolic expansion; wherein the methodfurther comprises exerting on the ventricle or ventricles that receivenegative pressure during diastolic expansion positive pressure at ornear the paint of maximum diastolic expansion of the ventricle orventricles.
 19. (canceled)
 20. A device for treating cardiac diseasecomprising: (a) a cardiac jacket adapted to fit generally around theheart of a mammal, the jacket comprising an inner layer proximal to theheart and an outer layer distal to the heart, each composed of abiocompatible material, the inner and outer layers coupled to form oneor more fluid-tight seals that define (i) one or more chamberscollectively generally overlaying the right ventricle (the right chamberor chambers), and/or (ii) one or more chambers collectively generallyoverlaying the left ventricle (the left chamber or chambers); (b) afirst fluid passageway linked to the right chamber or chambers; (c) asecond fluid passageway linked to the left chamber or chambers; (d) afluid reservoir linked to the first and second fluid passageways; and(e) a pump linked to the fluid reservoir and adapted to pump fluid fromthe fluid reservoir into right chamber or chambers and the left chamberor chambers and to withdraw the fluid from the chambers in a cycle toexpand the left chambers and/or the right chambers during systole andcontract the chambers during diastole to assist systolic pumping of theheart or diastolic refilling of the heart or both; wherein the chambersdo not cover the apex of the heart and in operation the jacket does notcompress the apex of the heart upward; wherein the one or more chambersoverlaying the right ventricle are fluidically separated from the one ormore chambers overlaying the left ventricle except through the fluidreservoir; wherein the one or more chambers overlaying the leftventricle are delimited in part by a seam coupling the inner and outerlayers and overlaying the anterior sulcus of the heart, and by a seamcoupling the inner and outer layers and overlaying the posterior sulcusof the heart; wherein the device is adapted to allow an operator to (i)adjust pressure or time course of pressure exerted on the left or rightventricle in diastole by the device or maximum expansion volume of theleft or right ventricle allowed by the device in diastole, or (ii)adjust the pressure or the time course of pressure exerted on the leftor right ventricle in systole by the device or the minimum volume of theleft or right ventricle in systole, or both (i) and (ii) and (ii);wherein the device is adapted to allow adjustment of the maximumexpansion volume of the left or right ventricle during diastole that isallowed by the device by altering the amount of fluid in the chamber orchambers overlaying the left or right ventricle at the point of maximumdiastolic expansion of the ventricle. 21-22. (canceled)
 23. The deviceof claim 20, wherein the device is adapted to exert different pressureson the left and right ventricles during systole.
 24. The device of claim23 wherein the device is adapted to exert pressure on the left or rightventricle in systole and substantially no pressure on the otherventricle in systole.
 25. The device of claim 20 wherein the device isadapted to exert pressure on the left or right ventricle duringdiastolic expansion of the ventricles before maximum expansion duringdiastole of the ventricle or ventricles against which pressure isexerted.
 26. The device of claim 20 wherein the device is adapted toexert negative pressure on the left or right ventricle during diastolicexpansion of the ventricles to assist the left or right ventricle withdiastolic expansion.
 27. The device of claim 26 wherein the device isfurther adapted to exert on the ventricle or ventricles that receivenegative pressure during diastolic expansion positive pressure at ornear the point of maximum diastolic expansion of the ventricle orventricles.
 28. (canceled)
 29. The device of claim 20 wherein the deviceis adapted to allow separate adjustment of the maximum expansion volumeof the left and right ventricles during diastole that is allowed by thedevice by altering the amount of fluid in the left and right chambers ofthe device at the point of maximum diastolic expansion of the ventricle.30. A system for treating cardiac disease comprising: the cardiac jacketof claim 20 wherein the cardiac jacket comprises at least twodimensional transducer elements; and a monitor electrically coupled tothe transducer elements; wherein the transducer elements are adapted tomeasure signals that allow determination of distance between the atleast two transducer elements and are adapted to transmit the signals tothe monitor. 31-36. (canceled)
 37. A method of treating heart failure bypassively restraining diastolic expansion, the method comprising: (a)implanting a device for treating cardiac disease comprising: (I) acardiac jacket adapted to fit generally around the heart of a mammal,the jacket comprising an inner layer proximal to the heart and an outerlayer distal to the heart, each composed of a biocompatible material,the inner and outer layers coupled to form one or more fluid-tight sealsthat define (i) one or more chambers collectively generally overlayingthe right ventricle (the right chamber or chambers), and/or (ii) one ormore chambers collectively generally overlaying the left ventricle (theleft chamber or chambers); (II) a first fluid passageway linked to theright chamber or chambers; (III) a second fluid passageway linked to theleft chamber or chambers; (IV) a fluid reservoir linked to the first andsecond fluid passageways; and (V) a pump linked to the fluid reservoirand adapted to pump fluid from the fluid reservoir into right chamber orchambers and the left chamber or chambers and to withdraw the fluid fromthe chambers in a cycle to expand the left chambers and/or the rightchambers during systole and contract the chambers during diastole toassist systolic pumping of the heart or diastolic refilling of the heartor both; wherein the one or more chambers overlaying the right ventricleare fluidically separated from the one or more chambers overlaying theleft ventricle except through the fluid reservoir; (b) pumping fluid inthe device with the pump to expand the right chamber or chambers and/orthe left chamber or chambers of the device; and (c) adjusting pressureexerted on the left or right ventricle in diastole; wherein theexpansion of the chambers of the jacket is not changed over at least 24hours.
 38. The method of claim 37 wherein after step (b) the methodcomprises measuring one or more physiologic parameters of the patient,and then based on the physiological parameters, executing step (c).